A new report from Amnesty International has found a surge in the number of executions taking place worldwide which means more people were killed by the state last year than at any point since 1989.
At least 1,634 people were officially put to death in 2015, and Amnesty estimates thousands of people were killed in China, where records are kept secret.
Iran, Pakistan and Saudi Arabia were responsible for almost 90 per cent of recorded executions.
With 28 people executed, the US came in at number five on the list, which is the country's lowest annual figure since 1991.
The majority of people put to death by hanging in Iran were prosecuted for drug-related crimes, including four who were under 18 at the time of sentencing, in violation of international law.
A change in the law to allow civilian executions in Pakistan in 2014 has led to what Amnesty described as a "state-sanctioned killing spree".
Saudi Arabia has also seen a huge spike in executions, the annual number of which have risen 76 per cent in 2015 on 2014. The usual method of execution is beheading.